Health is Wealth

Down Syndrome Is Most Common In Women Under 35, But Why?

Dr. Nayna Patel (R), a pioneer of reproductive surrogacy in India, conducts an ultrasound on 30 year old surrogate mother – Rinku Macwan, bearing twin babies, at Kaival Hospital in Anand, some 90 kms from Ahmedabad, on October 31, 2011. Commercial surrogacy, made legal in India in 2002 and popular among foreign couples who are unable to conceive, has provided a large source of income for some Indian women acting as surrogate mothers despite local stigmas and ethical debates. The United Nations says that by its best estimates the seven billionth baby will be born somewhere on October 31, and countries around the world have planned events surrounding the demographic milestone. AFP PHOTO/Dibyangshu SARKAR (Photo credit should read SAM PANTHAKY/AFP/GettyImages)

Dr. Baumer and Dr. Davidson also describe the variety of screening tests available during pregnancy, which include tests and ultrasounds done in the first and second trimesters, as well as the increasingly common cell-free DNA analysis. They went on,

Each of these screening tests indicates the likelihood that baby has Down syndrome. Although the Cell-free fetal DNA test is more specific and accurate than the other screening tests, it is not diagnostic.

They clarified that the only truly diagnostic prenatal tests for Down syndrome remain invasive testing using chorionic villus sampling, amniocentesis, and cordocentesis, which all involve using a needle to collect fetal DNA through placenta, amniotic fluid, or umbilical cord. Each of these procedures carries an increased risk of miscarriage that, according to the American Pregnancy Association, ranges from as high as one in 50 with cordocentesis to somewhere between one in 200 and one in 400 for amniocentesis.